New York: Friendship groups play a major role in a student's life and the density of ties that he/she shares with friends is associated with specific social and academic benefits, says a new study.

The study showed that friends can act both as resources and liabilities in an individual's academic achievement and also continue to be so even after college life.

"Contrary to conventional wisdom, students are quite savvy in recognising that friends can distract them and in strategically using friends to help them improve their academics. The most successful strategies, however, differ by network type," said Janice McCabe, Associate Professor at Dartmouth College in New Hampshire, US.

In the study, the researchers mapped the friendship networks of 67 students at a Midwestern university. They found that student friendships can be classified into three types of networks -- tight-knitters, samplers and compartmentalisers.

Students in the group of tight-knitters know each other, and refer to their friends as family and relied on each other socially. Academically, they were supportive and helpful.

However, they also had the potential to pull each other down academically, if they lacked academic skills and motivation. The potential for such negative influence reproduced race- and class-based inequalities, the study said.

Compartmentalisers have two to four clusters of friends, who do not know each other, and their network resembles a bow tie. They had separate clusters of friends: one or more for studying and one or more for having fun, with a good balance between the two.

They tended to be from the middle-class, and relied less on their friends to succeed in college than tight-knitters, the researchers noted.

On the other hand, students in the samplers' category have one-on-one friendships rather than groups of friends, with friends from different places remaining unconnected to each other. They are independent and did not rely on their friends for a sense of belonging. However, they were often socially isolated.

They were academically successful without the help of their friends, the researchers concluded in the paper published in the journal Contexts.